Patient Performance Status

Performance status is a numerical rating given to a patient’s ability to function in daily life, including the ability to care for oneself, engage in physical activity, and whether any assistance or medical care is necessary for the patient. Performance status scales are widely used in assessing the expected outcome of cancer (or prognosis).1

David Karnofsky and his colleagues described the first performance status scoring in a textbook published in 1948. The Karnofsky scale uses a scale between 0 and 100. A score of 100 represents normal activity, and a score of 0 occurs at death.2

In 1960, the Eastern Co-operative Oncology Group (ECOG) simplified the scoring system to five points. It is sometimes referred to as the Zubrod scale because C. Gordon Zubrod was the principal researcher. Later, a sixth point was added, with 0 denoting someone who is fully active and 5 occurring at death. The ECOG performance status is often used in clinical trials when enrolling patients to help keep study populations consistent. The performance status is also used to evaluate patient’s ability to function as a result of cancer treatment.1-3

Comparison of the Karnofsky and ECOG Performance Status Scores

Several studies have determined that both the Karnofsky and ECOG performance status scores are reliable. Studies have also demonstrated a high level of agreement across different raters for both scoring systems.1,3,4

ECOG Performance Status
Karnofsky Performance Status
0: Fully active and able to carry on all pre-disease performance without restriction
100: Normal, no complaints and no evidence of disease
90: Able to carry on normal activity with minor signs or symptoms of disease
1: Restricted in physically strenuous activity but able to walk and carry out light house work or office work
80: Normal activity with effort; some signs or symptoms of disease
70: Able to care for self but unable to carry on normal activity or to do active work
2: Able to walk and capable of all self-care but unable to carry out any work activities; up and about more than 50% of waking hours
60: Requires occasional assistance but is able to care for most of personal needs
50: Requires considerable assistance and frequent medical care
3: Capable of only limited self-care; confined to bed or chair more than 50% of waking hours
40: Disabled, requiring special care and assistance
30: Severely disabled; hospitalization is appropriate although death is not imminent
4: Completely disabled; cannot carry on any self-care; totally confined to bed or chair
20: Very ill; hospitalization and active supportive care are necessary
10: Declining, approaching death
5: Dead
0: Dead

Performance Status and Prognosis

Performance status scores are often used to help determine prognosis for lung cancer. Several studies that used the Karnofsky performance scale have determined that predicting survival is valid only for patients with scores less than 50. At scores of 30-40, patients had a survival time of approximately 49.8 days, while patients with scores of 10-20 had survival of approximately 16.8 days.5

The ECOG performance status scores also provide prognostic estimates at the lower levels of functioning. A score of 3 on the ECOG scale correlates to a survival of approximately less than 3 months, while a score of 4 correlates to an approximate survival of less than 1 month.5

Written by: Emily Downward | Last reviewed: January 2017.
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